锌与基因表达的研究进展

锌是机体所必需的一种微量元素,在细胞分化和生长中起着重要作用。细胞内的部分锌存在于细胞核内,在维持遗传稳定性和调控基因表达中起着重要作用。近年来,有关锌对基因表达的影响主要集中于转录水平,即锌通过影响转录因子(含有锌指域)的活性进而调控细胞增殖、分化及细胞死亡。本文就锌调控基因表达的相关方面作一综述。     

纳米氧化锌对断奶仔猪生长性能的影响

选用63头断奶仔猪,分为处理1组(3000mg/kg普通饲料级氧化锌)、处理2组(250mg/kg纳米氧化锌)、处理3组(500mg/kg纳米氧化锌)三个处理,每个处理3个重复,每个重复7头仔猪,试验期20d。结果表明:纳米氧化锌(500mg/kg)能显著提高断奶仔猪的日增重(与处理1组相比,提高9.91%),改善肉料比,有较好的经济效益。     

锌中毒对雏鸡外周血T-淋巴细胞的影响

200只1日龄艾维菌肉鸡随机分为4组，即对照组（每千克日粮含锌100mg）、锌中毒Ⅰ组（每千克日粮含锌1500mg）、锌中毒Ⅱ组（每千克日粮含锌2000mg）、锌中毒Ⅲ组（每千克日粮含锌2500mg），每组均饲喂日粮7周。以流式细胞术和酸性α-醋酸萘酯醇（ANAE）染色法观测外周血T-淋巴细胞的动态变化。结果，3个锌中毒组7周龄时，外周血T-淋巴细胞ANAE阳性率显著低于对照组（P〈0．05或P〈0．01），同时3个锌中毒组间比较也呈显著差异（P〈0．05或P〈0．01）。与对照组比较，锌中毒Ⅲ组2至7周龄和锌中毒Ⅱ组6、7周龄CD4^＋T淋巴细胞数量减少，锌中毒Ⅱ组、Ⅲ组2至4周龄和锌中毒Ⅰ组、Ⅲ组7周龄CD8^＋T淋巴细胞数量降低，CD4^＋／CD8^＋比值3个锌中毒组2、4周龄升高，6、7周龄降低。由此表明，锌中毒可抑制T-淋巴细胞的生成，降低其在外周血中的数量。     

铜、铁、锌、锰添加量对0～3周龄肉鸡生产性能和免疫器官发育的影响

将960只1日龄艾维茵肉仔鸡随机分为16组,每组4个重复,每重复15只;采用D-最优设计,以基础日粮含量为最低水平,以2倍NRC(1994)推荐量为最高水平,按16种方案添加铜、铁、锌、锰,研究不同添加水平对0～3周龄肉鸡生产和免疫器官发育的影响,以确定0～3周龄肉鸡日粮铜、铁、锌、锰的适宜添加水平。结果表明:不同铜、铁、锌、锰添加水平对0～3周龄肉鸡日增重、耗料量、料肉比、死淘率及免疫器官发育均无显著影响(P>0.05),说明基础日粮中的铜、铁、锌、锰含量能够满足0～3周龄肉鸡生长和免疫器官发育的需要。     

锌对鹅淋巴细胞凋亡和细胞增殖周期影响的研究

试验选用120只1日龄鹅随机分成4组，A组喂以玉米大豆为基础日粮未加锌的饲料，另3组在基础日粮中添加ZnSO₄·H₂O，使锌含量分别为40(B组)、110(C组) 和2000 mg/kg(D组)。应用流式细胞仪观测锌对鹅细胞周期和细胞凋亡的影响。结果显示锌添加量为110 mg/kg时，鹅血液淋巴细胞、胸腺、脾脏细胞的增殖指数和DNA含量最高。低锌和高锌饲料可以引起血液淋巴细胞的凋亡。     

Effects of Addition of Rare Earth-chitosan Chelate to Diets at Different Protein Levels on Sows and Suckling Piglets

The purpose of this experiment was to study the effects of corn-soybean meal diets with different levels of crude protein (CP) adding 200 g/t rare earth-chitosan chelate (RECC) on the reproductive performance of sows and growth performance of their offspring.A total of 60 sows at 90 days of gestation with good physical condition,parity and the expected date of birth were selected.Single-factor randomized block design was used,and sows were divided into 3 groups,20 sows in each group,1 sow each replicate.The level of diet CP and RECC were 17.55% CP,17.00% CP+200 g/t RECC and 16.00% CP+200 g/t RECC in control group,test group Ⅰ and test group Ⅱ,respectively.The test was started from the 90th day of gestation of the sow and ended at the time of weaning at 21 days.The sow litter performance and growth performance of offspring suckling piglets were studied.The final results showed that:Compared with the control group,sow's duration of the test groups Ⅰ and Ⅱ were significantly shortened (P<0.05),but the total litter size and number of born alive did not show significant difference (P>0.05).Postpartum weight loss of sows of the test group Ⅱ was significantly improved (P<0.05),but there was no significant difference in the interval from weaning to estrus (P=0.30).In addition,compared with the control group,sow's ADFI of test group Ⅰ and Ⅱ had an increasing tendency during lactation (P=0.08),and there was no significant difference in ADG,the weight of newborn and weaned piglets (P>0.05),but the diarrhea rate of suckling piglets was significantly reduced (P<0.05).In summary,under the conditions of this trial,when the CP level in the diet was 16.00% and with the addition of 200 g/t RECC,it could improve the reproductive performance of sows,shorten the sow's duration,and reduce the diarrhea rate of suckling piglets.It was of great significance to the improvement of the reproductive performance of sows.     

锌胁迫与缺锌对西府海棠叶片保护酶活性及膜脂过氧化的影响

以西府海棠(Malus micromalusMak.)幼苗为材料,研究了锌胁迫与缺锌对叶片保护酶活性及膜脂过氧化的影响。结果表明,锌胁迫及缺锌都严重影响西府海棠幼苗的生长,显著降低叶片叶绿素含量;并使叶片SOD、POD、CAT活性显著降低,MDA含量极显著升高,叶片相对电导率显著提高,表明已引起了细胞膜伤害。     

硼锌微肥对油橄榄花粉萌发及坐果的影响

田间试验结果表明：施用硼肥促进油橄榄花芽分化，花粉萌发率提高了74．1％，花期后的坐果率增加29．6％，产量增加14．0％；施用锌肥可以降低油橄榄硬核期和油脂形成期的落果率，分别降低18．5％和12．3％，产量增加12．1％；硼锌肥配合施用效果最佳，花粉萌发率提高了82．4％，花期后的坐果率提高了33．5％，硬核期和油脂形成期落果率分别降低了17．9％和14．8％，产量增加21．9％。     

氯化锌法颗粒活性炭新工艺、设备研究

本工艺以木屑为原料,采用氯化锌法在FS—Ⅲ型隧道式炭、活化炉中生产定型颗粒活性炭。中试表明,生产规模可达40—50t/年;苯吸附率可达25%—40%,耐磨强度≥90%;氯化锌耗量≤0.3tZnCl_2/t炭。